...Of the lenses mentioned so far, the Zeiss could be a good choice, although for less money an f2.5 Color-Skopar could be good. Being a wizened old photographer, I tend to select a 4-glass lens for better flare suppression - of all the lenses I own, the champ for flare suppression has to be a 360 mm f5.5 Tele-Xenar. Only 4 glasses and single coating, but it never flares even with the sun in the picture or more critically just outside the frame.

I certainly agree about 4 glass lenses and flare suppression. I do a lot of shooting towards and into the sun as well.

The original Voigtlander Skopars and Color-Skopars were classic 4 glass Tessar designs. The current Color-Skopars in Leica mount are indeed excellent lenses, but I am not aware of any that are 4 glass designs. For example, my 21mm f4 Color-Skopar is an 8 element 6 group design.